Into the Fold
by Hulihana
Summary: Castle gets officially welcomed into the team in a way even a writer wouldn't imagine. Beckett/Castle/Ryan/Esposito
1. Chapter 1

**Alright all, here's all you need to know before delving into this story. It's going to get kinky. It'll involve threesomes and more and will include slash (AKA M/M/F and M/M/M/F). If that is not something you wish to read about, please exit stage right.**

**Second, I do not own Castle, I simply watch it and write these lovely little stories that take over my mind.**

**Finally, this story is loosely based off of a kink meme from this past winter; once it becomes clear Castle will be around for a while, they initiate him to the team by their usual ritual for new team members, each taking their turn. You should also check out Twisha's story Initiation, because it's awesome, and is also based on the same premise. However, this one will have a decidedly different feeling to it than her's. Also, before you ask, yes I've spoken with her and have permission to write and publish this story.**

**Now please enjoy!**

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Castle sucked in a deep breath and then released it slowly, trying to dispel his nerves as he stood in front of Kate Beckett's door.

As the team had been packing up to head home from the precinct earlier that day, she had turned to him and invited him to her place for a 'team bonding exercise'.

If spending time outside of the precinct with Beckett wasn't enough to get his heart pumping faster than average, the strange look in her eye, as if she were assessing him, while she extended the invitation definitely would have done the trick.

Besides, team bonding? What the hell is that?

Finally deciding there is only one way to find out, Castle inhales again and raises his hand, pulling his fingers into a fist at the same time before knocking on her door in three short percussive bursts.

His pulse pounds in his ears as he waits… and waits.

It seems like forever, but in reality, probably isn't more than thirty seconds before Beckett herself pulls the door open, a small smile adorning her lips.

"Hey" he greets as he glances past her to see Ryan and Esposito seated on the couch in the sitting room just inside the doorway.

"Hi Castle, come in." she says, that same look as earlier now gracing her features as she steps aside, giving him space to enter her home.

He takes a look around noticing just how much her personality shines through in this place before his attention returns to the detectives, now all three seated on the couch, side-by-side. They've all changed since leaving the precinct and are dressed casually.

The guys are wearing jeans and t-shirts while Beckett has black leggings and an old NYPD hoodie on. He feels somewhat overdressed in his button-down and slacks but he doesn't have time to dwell on it as Beckett motions to the chair set across from the couch.

It seems a little out of place with the rest of her décor and he finds himself wondering if this is how the chair is always placed as he sits and looks up at Beckett, it's clear to him that she's running this show.

She seems to be deliberating for a moment and looks to the men on either side of her before turning to him again.

"Castle, we asked you over here tonight to take part in our version of team bonding. You may have noticed that we are an exceptionally tight-knit group and there's a reason for that. In order for you to join my team fully, you'll need to take part as well, but ultimately it will be your choice. Be warned however, that if you choose not to partake, you will never be a member of this team, regardless of what the mayor may say."

He didn't know what to make of her little speech. The butterflies that had resided in his stomach as he stood outside her door had now exploded into full blown anxiety as he tried to figure out what was really going on here. He thought he'd been on her team for the last month, but now he was being told that he wasn't?

Beckett continued to make direct eye contact with him, which was unnerving to say the least, and it appeared as if she was waiting for a reply. What was she saying again? Oh, right, he had a choice whether to do this or not. What was he supposed to be doing?

"What do I have to do?"

Images of all number of initiation ceremonies he'd seen in books and movies throughout his life passed through his mind's eye as he waited for her response, along with several new possibilities that were borne entirely from his own imagination.

A smirk curved her luscious lips as she looked at him, as if reading his mind.

"We aren't a college sorority Castle" she reminded him, her smirk growing wider.

"We're fully grown adults, with very different needs and agendas. My team's way of remaining close is by providing for one of those basic needs. Can you guess which one that may be?"

And there's that calculating look again, but this time, instead of just staring directly into his eyes, her hazel orbs slowly travel down the length of his body from the top of his head to the soles of his feet back up again.

Did Kate Beckett really just check him out?

He glanced to Ryan and Esposito on either side of her, as if asking the men for help, but both of them were watching him impassively, as if they didn't have an opinion on the matter.

"Um, getting supper together? Are we going to cook something?" he asks, deciding the play it safe.

"Espo, do you know how to cook?" Beckett asks, finally turning to address her junior detective.

The Hispanic man scoffs and shakes his head, "Nothing doesn't come out of a box."

"What about you Ryan?"

"Well, I can grill a mean burger but that's about it."

"I guess that's a no to cooking supper Castle. Any more guesses?"

He looking from one person to the next, waiting for someone to give him a clue as to what he was supposed to say, but they were trained to have unreadable expressions, and no one was providing him with any help.

Finally, he mutely shakes his head, all of his normal bravado abandoning him in this moment of confusion and nervousness. He feels like a child again, being scolded by a teacher for not having the right answer to the problem set in front of him.

"Then let me give you a little hint. Remember when I told you that you had no idea?"

And just like that he was lost in a memory of Beckett sauntering away from him, her hips swaying enticingly as her unique scent lingered in his nose.

"I'll take that as a yes." Oh, and now she was laughing at him. Great. Just great. What was he missing?

"Castle, the boys and I have a very unique relationship. Here, in this place, we are free to connect with one another on a physical level as equals. If you choose to join us, you will know exactly what you have been missing."

Was she really saying what he thought she was? Connecting on a physical level, that sounded like…

"Rick, the three of us engage in a sexual relationship on a regular basis. Right now, at this moment, you have the option to join us. If you choose not to do so, you will never be truly accepted as a member of my team."

Castle collapsed back into his chair completely flummoxed. Really? This had really been happening the entire time he knew them and he'd never even suspected, and now they wanted him to join in. Was he dreaming?

The detectives just watched him, as if knowing that he needed a moment to process what he had just been told. They probably did know.

"How- How long has this been going on?" was the first question of the hundreds that were running through his mind to leave his mouth.

"Since I was a rookie." Beckett spoke once again. "I then introduced the boys much the same way I was. Similar to this right now."

"What happens in this apartment stays in this apartment bro" Esposito finally speaks up, levelling his dark stare on the writer and Castle can't help but feel the veiled threat inherent in the man's comment and so he nods his understanding.

"So if I choose not to join you-"

"Then you will never be a true member of my team. I can't make you leave the 12th, but only I can say if you are actually one of us."

The thought of being at the precinct but not being a part of the group seated in front of him was daunting, but at the same time, he wasn't so sure about this. If it was just Beckett, well, he'd agree in a heartbeat. He'd even had a threesome before, but that had been with two other women. He had never had sex with another man, nor really felt the inclination to. Was it really worth all this just to remain at the precinct?

Sure, he was hoping that someday Beckett would give him a chance to take her out, and after she had opened up to him about her mother's murder, he had thought they'd been getting closer. He even enjoyed helping them solve the murders and the place was a goldmine of inspiration for his books. He just didn't know if he could do this.

Seeming to sense his indecision, Beckett spoke again.

"You will get the option, for the first time only if you so choose, to only watch. After that though, you must be a participating member. This option is only open to you if you decide to go through with joining our team, however."

Once again his gaze tripped from one set of eyes to the next, clear blue, to chocolate brown, to mystifying hazel.

As their gazes meet, she asks the question, "So what's it going to be Castle, are you in, or are you out?"

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**First of all, how did you like this little introduction, does it seem to make enough sense? I promise we'll get to the fun part soon, but before that happens, I need your help. See, originally I planned to only write a couple chapters with the four of them and finish this story off, but somehow I got hijacked by this idea of having Castle watch Beckett, Ryan, and Esposito first before joining in. What do you guys think, should I stick with the original idea and just do the entire group, or should I split it up into two completely separate scenes? That isn't to mean I will only do one scene with the entire team regardless of which route this story takes, it all depends on how inspired I am to write throughout this process. I need your opinions on this one and then I'll get the next chapter out to you soon.**


	2. Chapter 2

_The vote was unanimous. Here's to this chapter being everything you hoped it would be. I also want to quickly thank everyone for your support of this story, I've really been surprised by the amounts of favs and follows that I've received already. Oh, and I forgot last time to tell you all as a reference point that this story takes place around 'A Chill Goes Through Her Veins' 1x05. _

**And again, a warning. The following chapter contains sexual situations. It also contains a threesome and various other unusual sexual acts, if this is not something you wish to read about, or you are underage, please read no further. Thank you.**

* * *

This is it. This is his chance to earn his place at the 12th and have an idea what exactly it is to be with Detective Kate Beckett. He just never imagined that when his chance came, Ryan and Esposito would be sharing the bed with them.

Really though, he already trusts these people with his life, and the stirring in his groin at her words proves that at least some part of himself wants this, but still, can he really do something this insane. He's had his fair share of wild sex, yes, but this is something else entirely.

The sound of Beckett clearing her throat breaks him out of his thoughts and he looks up in surprise to realize that they're still waiting for his answer.

Taking one more look at the group, decision made, he answers, "I'm in,"

He can't help but notice the way her eyes light up at his answer, "but I want to watch first."

Once again her eyes give her away, those hazel irises revealing that she'd expected nothing less of him.

"Very well. Let's go boys." And just like that it's as if a switch has been thrown and the formality of the situation has completely disappeared, just by the breathy quality in her voice Beckett issued her command.

The three detectives stood and quickly, eagerly, made their way towards what was undoubtedly Beckett's bedroom, leaving Castle to stare after them for a moment before finally standing to follow.

He enters the bedroom to find them all in various states of undress.

Castle's eyes widen at the sight of Kate Beckett clad in a navy blue lace covered bra as she works to take off her own pants to reveal a matching pair of bikini cut panties.

His attention is drawn away from the female detective by her two junior detectives, both of whom are now down to their socks and boxers which are quickly divested of.

Both men appear to already be semi hard, although one look at Beckett and who could blame them, and neither is lacking in size. A small wave of apprehension rolls through him as he watches the other men undress with the knowledge that at a not too distant time, they intend to fuck him.

Beckett turns back to Castle and winks at him before stepping towards Ryan and Esposito with a predatory air about her.

She glances from one to the other until Esposito takes a small step back, a sign it would seem, as she immediately drops to her knees in front of Ryan and takes him into her hands.

Castle watches as the younger man groans and his eyes roll back into his head as Beckett strokes his length with her hand and reaches the other up to lightly tickles her fingernails over his balls.

Seemingly done with teasing, she shifts forward and takes the Irishman into her mouth and Castle can't help but wish that it was he himself that were feeling the detectives talented lips and tongue dancing over his manhood as his blood runs south.

Not content to simply watch, Espo circles around the engaged couple and comes to stand behind Beckett.

He then drops down to the floor and nudges her thighs wider apart so that she's settled closer to the floor, and he has room to maneuver as the man lays on his back and places his head between her spread thighs.

Esposito props himself up on his elbows slightly so that he can reach and even Castle can hear Beckett's moan when the Latino slides his tongue through her folds.

The writer watches the trio in fascination as they all move and shift together. He can actually see how this threesome requires teamwork, and of course huge amounts of trust among the three detectives.

His moment of philosophical thought ends abruptly when Beckett lets Ryan's length slip from her mouth and she utters a strangled cry, her body thrashing wildly over Esposito's.

All three men watch her openly as she writhes and whimpers in the throes of passion, until she slowly comes down from her high.

Unable to ignore his own arousal any longer, Castle spares a glance down to his tented slacks so he can remove them and pull his own member through the slit in his boxers.

He takes himself in hand as he watches the detectives disengage from one another and rearrange their positions.

This time it's Ryan who drops to his knees in front of Esposito and takes the man into his mouth eagerly, sucking and licking at the head as if it was a melting ice cream cone.

Instead of immediately joining in on the action, Beckett walks over to the bedside table and pulls out a bottle of what Castle guesses to be lube.

His assumption is proven to be correct when she kneels behind the Latino detective and opens the bottle, spreading some of the lube on her fingers before pushing one into his ass.

The man's hips jolt forward at the unexpected intrusion, but Ryan doesn't even flinch as he takes more of the other man's length down his throat.

Beckett grins wickedly and slowly thrusts her finger in and out before adding a second one.

This time Esposito seems to know it's coming and doesn't even react when she starts to scissor her fingers inside his body, stretching his opening wider.

Castle watches with rapt attention as she pours more lube onto her hand and enters her junior detective with a third finger, thrusting them in and out of his ass slowly and methodically.

The writer finds himself fisting his member and pumping it in time to her thrusting fingers.

She must decide that Espo is ready because she removes her fingers and stands. Another signal it would seem, as Ryan immediately stops sucking on his partner's length and moves to lay on the bed.

Beckett hands him the bottle of lube and walks over to stand beside Castle, only a flick of her eyes towards his engorged manhood giving her away, before she turns to watch along with him.

They watch as Esposito scoots backwards to Ryan's position in the middle of the bed, and takes the Irish detectives member into his hand and places it at his entrance. Ryan grabs his partner's hips and helps guide him down until the Latino is seated firmly, with his partner's manhood buried in his ass.

"We're all clean, and get tested every six months." Beckett explains to him in a soft voice as they watch Esposito begin to ride his partner.

"Also I'm on the pill, although we do often use condoms."

Castle nods to show that he understands, still entranced by the sight of the two men moving together on the bed. Ryan enjoying the view of his ass as Esposito rides him in reverse.

"Soon, it'll be your turn Castle." She states with another long glance at his member before walking away back to her junior detectives.

His member pulses as her words register in his mind. After having seen them in action, seeing the care they take for one another and the sensuality of this moment, Castle can't wait until it's his turn to join them.

He watches as Beckett approaches the bed and places a hand on Esposito's shoulder, pushing the man down so that he is laying flush with his partner, his back to Ryan's front.

The two men pause in their movements and both watch as their senior partner joins them on the bed and moves so that she's straddling the both of them.

She reaches down to hold Esposito steady beneath her and then sinks down onto him, her eyes fluttering as his length disappears inside her body.

After a moment for everyone to adjust, Castle watches as they all begin to move in tandem. Ryan is rocking his hips to thrust himself in and out of his partner's ass while Beckett rides him from above, her weight pressing the man down into Ryan on downward movement.

Meanwhile, the writer watches, awestruck, his hand fisting his shaft in time with their movements. Somewhat shocked at himself by just how easily he is finding it to get off to watching these people he's worked with for the past month having sex. Castle is suddenly glad that he opted to join their team instead of walking out the door and out of the 12th forever.

He's so entranced by the sight before him that his orgasm, when it comes, takes him by surprise. A cry of ecstasy leaving his lips as milky ropes of semen erupt over his hand and Beckett's wood floor.

His high goes unnoticed by the three detectives bound together on the bed as short moments later first Beckett and then the two men let out their own cries and grunts as they all collapse in a shuddering pile on the bed.

Finally, Beckett rolls away from the two men to lay beside them on her back, inadvertently giving Castle a view of her swollen and aroused core.

It takes Esposito a few long seconds more to recover before he too moves from his position to the other side of Ryan until they are all three laying side-by-side on the bed, breathing heavily.

Castle can no longer bring himself to just stand by and watch passively. Three strides of his long legs have him across the room and standing at the foot of the bed, gazing down at the recovering detectives.

His eyes are drawn to Beckett's weeping core, and while some corner of his mind is desperately trying to remind him just how depraved this is, the rest of him just wants to know. He locks eyes with the woman for a moment before dropping to his knees at the end of the bed and grabbing her legs to slide her body over the comforter towards him.

Her body bared to him, and her ass resting on the very edge of the bed, he places her legs on his shoulders and leans forward for a closer look at the aftermath of her encounter with the two junior detectives.

The smell of sex is heavy in the air around them, but no more so than right here, right now, as Castle leans forward to take his first taste of Kate Beckett.

As he works his way diligently through her folds, cleaning her body of all traces, he works to separate the taste of her arousal from that of Esposito's release.

It doesn't take long before the over-sensitized detective is writhing and moaning above him, her legs tensing and relaxing over and over again where they're draped over his shoulders.

Finally satisfied that he has cleaned all traces of the other man from her, he suctions his lips around her clit and brings two fingers to her entrance, taking note of the way she whimpers when he begins to thrust them into her.

Her legs clamp around his ears as he finally brings her to a peak and gently eases her down the other side before withdrawing his fingers from her body and letting her legs fall so that her feet are resting on the floor.

He hadn't realized that Ryan and Esposito had both moved from their places on the bed while he had been otherwise occupied with Beckett and were now partially dressed, although their attention was still focused on himself and their senior partner.

Standing, Castle too tucks himself back into his boxers, a difficult feat now that he's once more partially aroused. He then moves to join the other men watching Beckett, waiting for her instruction.

"Tomorrow Castle. I expect you to be at the precinct to help us with the Wilder case and then tomorrow night we'll all meet back here again." She says, propped up on her elbows on the bed, still unashamedly naked.

The men finish redressing and all three make their way from the apartment without another word.

Castle can't help but wonder what exactly the next day holds in store for him, or if he'll even survive after everything he's witnessed today. One thing is for sure though, it would be one hell of a way to go.

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_Thoughts? Suggestions? Let me know._


	3. Chapter 3

Once again, Castle finds himself standing outside Detective Kate Beckett's apartment nervous as hell, but unlike the day before, now he knows exactly what is waiting for him on the other side of the door.

He holds a bag in hand as instructed. No work the next day apparently meant the detectives intend to play all night long, and he will be right there with them this time.

Despite the nerves fluttering in his stomach, there is also a healthy surge of arousal burning its way through his system as he wonders what the night ahead holds in store for him and the top homicide unit of the 12th precinct.

As if she had known he was there all along, Beckett opens the door mere seconds after he knocks and then turns and walks back into the dark depths of her apartment towards the doorway that he now knows conceals her bedroom.

Castle follows her like an eager puppy, closing and locking the door quickly behind him before rushing after the alluring detective.

He enters the bedroom to find that the other men have once again beaten him there, and this time, they are already naked and waiting, the sight of their ready, engorged cocks sending clashing waves of apprehension and arousal through the writer from head to toe.

Beckett reappears beside him, as if from nowhere, and gently pries his bag from his fingers.

"Take off your clothes Castle." She instructs as she takes it over to set with two others beside a chair in the corner of the room.

It wasn't until she bends to set the bag down that he realizes she is only wearing a loosely tied satin robe that typically hangs to her mid thighs but is currently rising deliciously to uncover a tantalizingly teasing glimpse of her curves.

The resulting tightening in his pants reminds him of her command, and he hurries to comply, grabbing the hem of his shirt to pull it quickly over his head and let it flutter down to the floor. The shirt was quickly followed by his pants, for which he hadn't even bothered wearing a belt this evening.

Standing now in just his boxers, he raised his eyes to meet those of the detectives, all three of whom were now watching him closely.

He trusts these people with his life, he reminds himself, trying to banish the nerves from his system and embracing the arousal that is pooling low in his stomach.

Locking with the last pair of hazel eyes, he lets his fingers trail to the waistband of his boxers, and slides them down over his hips before letting them too fall to the floor.

Beckett holds eye contact with him a heartbeat longer before dropping her gaze to his manhood, already semi hard just from seeing the naked and partially naked detectives in room with him and knowing what they intended to do to him tonight.

The sight of the female detective licking her lips as she gazes upon his semi hardened length is nearly enough to undo him right then and there, but he controls himself with a tightly held leash born from years of experience, and waits for their next instruction.

Esposito is the first to move once the writer has finished undressing, motioning Castle towards the bed.

Castle pauses, unsure once more; the silence in the room unnerving him. It's not until he sees Beckett move out of the corner of his eye that he understands a little of why the other two men are so speechless. He gazes upon her as she slowly slips the robe from her shoulders and lets it flutter to the floor in a pile of sensual silk.

She's just as beautiful as he remembers, but now can actually take the time to look, to catalogue every inch of her bare skin. These detectives get to spend time with this magnificent specimen of a woman on a regular basis, and Castle finds that he's willing to do anything she wants for the privilege to do the same. Of course, it also means full access to the twelfth, but with her standing bare in front of him, Castle finds that he and certain parts of his anatomy are much more interested in full access to the alluring female detective at this exact moment.

The woman walks around her junior partners to the bed and sat at the end of it before scooting backwards a little so that her feet were just at the edge, Castle scrutinizing her every move just as closely in her bedroom as he does out in the field.

Again, Espo motions him towards the bed, and this time, he goes, following the siren song that is a naked Detective Beckett.

He stops at the end of the bed, looking back and forth from Beckett to Esposito, unsure of what to do next. "Uh, guys?"

"Bend over the bed Castle." The man instructs, moving to stand next to the writer while Ryan moves to sit behind Beckett near the headboard.

Oh God, this was it. He was really about to let Esposito fuck him. But, doesn't he trust these people with his life? If he trusts them to protect him out in the field, then shouldn't he be able to trust that they won't hurt him here either?

Castle takes a deep breath and bent at the waist until his head and chest were resting on the bed beside Beckett.

He feels exposed, standing this with his ass in the air, knowing what was going to happen, and since the bed was shorter than his legs, he felt even more exposed since it placed his head below his hips.

"Like this?" he asks, looking back over his shoulder to smirk at the Latino detective, trying to diffuse the tension of the situation with humor, the best way he knows how.

"Over here Castle" he hears and looked up at Beckett in surprise to see her pat a hand against her thigh and giving him an odd look.

"You're too tall for this bed," she goes on to explain, "you need to have your upper body higher or you aren't going to be comfortable or able to relax."

He finds himself not quite able to believe what is happening as he moves to his left and finds himself with his head resting in Kate Beckett's lap. Sure, he'd done more than just lay his head in her lap the night before, and he could smell the musk of her arousal again now, but this seemed so much more intimate than that act from before had been.

When he moves his head so that he can see her, he finds she looking at him critically, studying him "Ryan, hand me a pillow" she instructs, turning to face the younger man. Her body shifts slightly below Castle and he gets a wonderful view of her glistening folds when her legs part just the tiniest amount before she is turning back to face him once again.

"Lift up Castle."

The writer complies and allows her to place the pillow below him, biting his tongue to hide a groan of disappointment that she has hidden the treasure trove that he knows is awaiting him between those creamy thighs.

"How does that feel? Is that comfortable for you?" she asks, breaking him out of his misery.

Castle stops to really consider his position for a moment before indicating that, yes, he is comfortable with a nod.

Almost immediately after his nod of agreement he feels hands on him, kneading his flesh.

"Take some breaths Castle. Try to relax." Beckett says in a decidedly softer tone than before and he can't help looking up at her in surprise at the warmth he has never before heard in the woman's voice. At least not directed towards him.

His thoughts of Beckett are short lived however, when he feels Esposito behind him part his cheeks and begin to circle his puckered hole with a finger already liberally coated in lube that the other man must have retrieved while he was getting comfortable.

The anxiety he had felt before rushes back in full force as he knows the other man is preparing to enter him for the first time.

Unable to help himself, Castle reaches out for Beckett's hand that is resting beside his head at her side.

Surprisingly she doesn't object, or threaten to shoot him, as he thought she might, instead flipping her hand to twine her fingers with his and giving it a comforting squeeze.

Castle takes a deep breath, making a conscious effort to calm himself.

The moment he lets the breath out, he takes in another as a gasp when he feels the burning intrusion of Esposito's finger inside his body.

The detective doesn't move right away for which Castle is grateful. If this is how much a single finger made his virgin opening burn, he can't imagine what it will be like when the detectives decide it's time to actually fuck him.

Beckett gives his hand another squeeze, giving himself something to anchor to and help bring him out of his spiraling thoughts just as Esposito begins to slowly thrust his finger in and out of his tight asshole.

The writer gasps again, but this time less in discomfort and more in surprise at the feelings that the single finger in his body is awakening.

Castle finds that he is hardening again in no time at all as the detective teases the sensitive nerve endings held in his ass. He can't stop himself from bucking his hips when the other man finds his prostate and rubs that maddening digit over and around it again and again.

He jerks his hips forward again, away from the detective when the other man unexpectedly slips a second finger in to join the first and clenches his eyes tightly shut against the warring sensations the intrusion is causing in his body.

The sound that escapes his lips, a mix between a mewl and a whimper, only serving to highlight the turmoil within the author.

"Shh, relax" Beckett speaks again, that same softness underlining her tone as she brings her free hand up to trail her fingers through Castle's formerly perfectly coifed locks.

Castle finds himself lost in the liquid hazel of the woman's eyes and barely notices when Esposito begins to scissor his fingers inside his ass, stretching his muscles deliciously until his eyes began to flutter and he had to fight to keep them open.

His reaction is less pronounced when a third finger is entered into his formerly tightly puckered hole, now well stretched and lubricated from the detective's ministrations.

The writer surprises himself at the whimper that falls from his lips when Esposito withdraws his fingers from is body, leaving him feeling utterly empty and wanting.

The soft snick of an opening bottle has him tensing up again as he watches Ryan lean over to get into the side table and hands a condom to Beckett.

The woman quickly rips the foil package open with her teeth and Castle can see Esposito step up beside him out of his peripheral vision to allow the female detective to roll the latex sheath down over his length.

He waits in agony of the unknown for what feels like hours, but in actuality is probably less than a minute as he can hear Esposito spreading lube wetly over himself.

"Are you ready Castle?" the detective asks, Castle nearly jumping when he feels the other man's hands once more on his posterior.

He looks up and sees the encouragement, unstated but clearly readable in Beckett's eyes and those of Ryan over her shoulder and he finds himself giving a nod of consent once more.

Despite his best efforts, he knows he tenses up upon the foreign feeling of the other man's cock pushing between his cheeks to rest against his puckered asshole.

"Easy Castle, breathe." Beckett reminds him, resuming the comforting movement of her fingers in his hairline as Esposito pauses, just letting his head rest against Castle's opening.

"No, I want you to push out against me for a moment bro." Espo instructs.

As soon as Castle complies and clenches his inner muscles, pushing against the intrusion in what feels like a natural reaction, he feels the force of the other man pushing back against him.

"Now, stop fighting it, relax." Esposito instructs.

Once again, Castle does as he is instructed and as soon as he stops pushing against the intruding force, the head of Esposito enters his ass.

Despite having been thoroughly prepared and stretched out, the writer isn't prepared for the burning and the slight pain that accompanies the strange feeling of having something as large as another man's cock inside his body.

A single, solitary tear escapes his eye as he breathes heavily, trying to become accustomed to the intensity of this new feeling.

"Are you alright?" Beckett asks, bringing their joined hands up to brush the tear from his cheek as she looks down at him kindly.

"Y-Yeah" Castle shudders out on a long exhale, finding that the pain is quickly subsiding, leaving behind only the feeling of being so incredibly full.

Beckett looks up and gives a nod to her junior detective who then begins to move within the writer.

"Oh, God." Castle chokes out as the younger man rocks his length a little at a time, slowly pushing himself further inside his body.

Any thought of pain has vanished, leaving behind only the fullness and the same stimulation that Esposito's fingers had created, but magnified by a hundred.

"Easy Esposito" Beckett warns, but it's in vain. There's no need to warn the man to slow down as he is already seated deep inside the writer's rectum and Castle is loving every moment of it.

The trio rest, unmoving now as if absorbing the moment. Beckett is still trailing her fingers through the writer's hair while Esposito is running his hands up and down his back while he's buried fully inside his tight heat.

That's when the detective begins to move in earnest, pulling back only to thrust in again, causing Castle to groan loudly when he feels the man's ridged length passing over his prostate.

Castle is hard as a rock now and as the Latino continues to move, prodding and stimulating his insides, he finds that he desperately needs the same for his own length.

While curious to know if he could come just from getting it up the ass alone, now isn't the time to find out he decides hurriedly and begins rutting against the end of the bed, rubbing his hardness against the soft quilt that has slipped slightly down the end of the bed.

"Ryan, grab another condom. Castle, don't you dare make a mess all over my blankets." Beckett growls, as she notices the man's movements in counterpoint to the thrusting of the man behind him.

Esposito stills inside him long enough to open the new condom and reach around Castle to roll it down over him before beginning his movement again, but he retains his grasp on the writer's member and begins to jerk his length as he thrusts into him from behind.

Castle is the first to release a strangled groan minutes after Esposito wraps his hand around his length, as he finds his release, his body jerking and spasming under the other man's ministrations.

The feeling of Castle clenching down on his length and reaching his peak below his is enough to send Esposito over as well, and he buries himself in the writer as he reaches his own orgasm.

Esposito collapses over Castle's back as both men rest their weight on Beckett's legs while they catch their breath and she runs her fingers soothingly over their cooling skin.

A moment later, Esposito is recovered enough to stand and he frees his length from inside the other man's body.

He leaves to dispose of the condom, but as Castle moves to stand and do the same, he finds the formerly soothing presence of Beckett's fingers are now holding him down with a commanding hand on his upper back.

"Nuh uh, Castle. You aren't done yet." She says, smirking at him as Ryan moves from where he's been watching the action behind Beckett and comes to stand behind the writer.

Castle whimpers but he isn't sure if it's from excitement over getting to experience another man filling him so deliciously, or because he truly isn't sure he can go another round right now.

Either way, it doesn't appear as if he's going to be given the option when Ryan grabs him by the hips and slowly slides his length into the writer's bowels.

Ryan's hips slap wetly against Castle's ass as he begins to thrust, the writer's body covered in a thin sheen of sweat from his earlier activities with the Irishman's partner.

"That's good Castle. You've done well so far." Beckett praises, a new husky quality to her voice as she watches the writers body sway with the force behind her subordinate's thrusts.

It doesn't take Ryan more than a few minutes to find his release after having watched the other two men rutting against each other earlier, he was already close when he first pushed his length inside Castle's thoroughly used hole.

The fact that the writer was now pushing back against his every thrust, increasing that power behind his movements and meeting him so enthusiastically didn't hurt either.

Castle closes his eyes as he feels Ryan grab his hips and slam his own against him as he grunts through his orgasm.

There's a decidedly strange feeling though when Ryan pulls out of him, and it takes the writer a long moment to realize that the difference is that Ryan didn't use a condom.

The strange feeling is the Irishman's sticky release leaking out of his well-used asshole and dripping slowly down over his own cock and balls.

Castle takes several long moments to recover, unsure if his shaky legs will hold his weight if he tries to stand straight and walk, but he needs to take care of his own condom.

As if she's reading his mind, Beckett wraps her delicate fingers in his hair and pulls up slightly so that he raises his head to meet her eyes.

"Go take care of that, Ricky, and then it's my turn." She purrs, wicked smile firmly in place.

* * *

_A/N: A bit of a delay but here it is, the next installment. There's one more chapter yet after this. In considering how far to take this story, I sort of stumbled upon an idea that would lead to a lengthy sequel building upon the events in this story, but, you know, with an actual plot. What do you guys think, would you be interested in reading more? And please, let me know what you think of this chapter and story as well, sequel or not, I always want to be able to improve my writing and try to give you guys as much of what you want as I possibly can._


	4. Chapter 4

"Go take care of that, Ricky, and then it's my turn." She purrs, wicked smile firmly in place.

Castle just stares at her for a moment, some distant part of his brain wondering if he shouldn't be pinching himself to make sure that this hasn't all been some elaborate dream.

The flash of irritation over Beckett's face when he doesn't immediately do as he's bid, however, reminds him that whether it's a dream or not; he's not complaining either way.

The man rushes to the bathroom to remove the condom, his face lighting up in a grin that would rival any child waking up on Christmas morning. His mood at this moment in time is very similar as well, although in a much more R-rated way.

Shaking himself from his thoughts once again, having been staring at himself absently in the bathroom mirror, he walks back into the bedroom.

A sense of disappointment floods his system when he walks through the ensuite doorway to find that while he has been gone, staring into space, Esposito has apparently taken his place with Beckett. He walks in just in time to see the woman lowering herself onto the other detective's hardened length as if preparing to ride him in reverse.

He's still standing in the doorway, just watching, unable to believe that after everything, he's lost his chance to finally be with Beckett. Of course, his experience with the boys was great (much better than he expected, although he had always wondered what it would be like to be with a man) but really the main event for him tonight was when he finally got to experience the passion of the fiery female detective.

"Castle, come on. We're waiting." Breaks through to his conscious mind and he looks up in surprise to see that Beckett is once again glaring at him, still ensconced by the arms of her junior detective.

He meets her steady gaze, confused, but will to go with the moment and makes his way across the room toward the couple.

She beckons him forward, her legs spread open revealing her slick folds to his observant gaze once more. And right now? He's observing that she hasn't taken Esposito into her center as he had believed.

"I told you it was your turn Castle." Beckett murmurs once he's standing in front of her, his body between those never ending legs of hers; her gaze is far to knowing and he wonders just how much he's telegraphed to Detective Beckett in the last minutes.

Regardless, he finds that his current position allows him everything he's hoped for since he first set eyes on her. And more, he concedes his eyes flickering to Esposito behind her and Ryan off to his left. After tonight, he really will be a part of this close-knit group and he finds that reality is far better than any scenario in his imagination.

Castle places both hands on her legs, just above Beckett's knees and he can't cover a slight smirk when he hears here breathy exhale as he slowly slides his hands up her body. Nor her groan of disappointment when he skips right over her center, his fingers dancing instead over her hips and up to her toned stomach.

He continues his exploration, cataloging her every twitch and sigh as he continues upwards until he reaches her pert breasts. The writer smiles as he runs his thumbs over both of her hardened nipples, testing the weight of her in his hands and finding that she fits perfectly against his palm.

"Castle, come on." She groans and he can't help but compare it to the exact words she spoke only minutes before, but now in a low, breathy tone that he finds he enjoys much, much more.

"As you wish my dear Detective." He answers, removing one hand from its place on her chest to take himself in hand and find his position at her entrance.

Castle stares into her darkened eyes, now swirling brown with flecks of gold and emerald green as he slowly enters her.

She's so tight; he once again finds himself doubting that this is reality, until he realizes that some of it can be attributed to the other man who has remained still, buried inside of her this entire time.

As he finally finds himself encased in her hot, wet core and his eyes break their contact with Beckett to flick towards Esposito, he nearly jumps when he feels the Hispanic man begin to move.

Castle was no stranger to the concept of having more than two people in one bed, he'd had more than one threesome in his younger days, but never had it been with another man. Never had he felt someone else moving while he was inside a woman.

In the split second it took him to get over his shock, Castle finds that this was something he could really, really get used to.

In all reality, he probably doesn't even have to move and he'd find himself exploding with release, but that wasn't what he wants at all.

The need to remedy the situation is overwhelming and in that moment, nothing could stop the writer from placing his hands on Kate Beckett's waist and beginning to thrust.

Beckett can't really do much from her position between the two men, but with the way she's writhing as they finally find a rhythm that suites all three of them, that may well be a good thing.

Castle is lost, floating in the blankness of sensation. There's no way he would possibly remember that there is, in fact, another person in the room with them until he notices the presence that is at his elbow.

Barely turning his head towards Ryan in acknowledgement, he feels an irrational surge of annoyance that the younger man dares to interrupt an experience that is so bizarre it just had to be a dream. One that he never wants to wake from, but a dream nonetheless.

Annoyance quickly makes way for confusion though when the blonde meets his eyes with his own baby blues and then he rises, standing somewhat shakily on his feet as the mattress rocks beneath him.

Castle watches as Ryan moves to stand with his feet on either side of his fellow detectives and the writer realizes that he was fully recovered from their earlier coupling.

His hips continue to move, almost without his consent, and certainly without his direct thought as he takes note of Ryan's hardened member standing proudly in front of him.

He realizes without being told what the detective has in mind and finds that; after today, not only does the idea not repulse him, but also somewhat intrigues him.

Taking one hand from where they are still positioned on Beckett's waist, he cups Ryan.

Tentatively, he leans forward, eyeing the offering put before him.

Deciding just to take the bull by the horns, Castle opens his mouth and engulfs the head of the other man, running his tongue over it in a copy of what he himself has experienced before.

Ryan grunts and thrusts forward slightly, sliding more of his length past the author's lips.

Castle considers the foreign taste on his tongue. It's musky and somewhat tangy, but not altogether unpleasant.

He finds it hard to focus on both the cock in his mouth and his own that is now forcefully plundering Beckett's molten hot core. Not to mention the tingling that is building in the base of his spine, letting him know that he is getting close.

He is nothing if not egotistical though and even now, refuses to find his own release until the woman beneath him has peaked first. How she's even held out this long he'll never understand.

He pumps the portion of Ryan's shaft that he can't get into his mouth without choking with his hand and licks at the engorged head somewhat desperately.

If only he can finish getting the other man off, then he can focus on the woman writhing beneath him and bring this whole experience to a spectacular conclusion.

Ryan's has a hand tangled in the writer's hair, but he isn't holding Castle down. He remembers with a sudden jolt what this entire thing is all about. Trust and commitment to the team. While undoubtedly a pleasant experience, hell who is he kidding? It's amazing. But all the same, this isn't just about pleasure, it's about really knowing the people who you have entrusted to have your back, to save your life in certain situations.

Of course Ryan wouldn't be holding him down. This isn't about control. It isn't about coercion. It's simply about knowing these people inside and out, literally. And now they've accepted him. Wow.

The writer's inner musings are interrupted when Ryan gasps out a warning and while some masculine, alpha male part of his mind cries for him to pull away; he finds that the majority of him doesn't want to do it. Certainly a part of his decision to remain in position as Ryan lets out a strangled moan and releases his load down Castle's throat is because he's curious. Curious what it will be like, but another deeper part of his soul is drawn to these people and he wants to truly be one of them in every sense. And that means not shying away when things get… messy.

The Irish detective moves away to give the remaining trio room as they gasp and grunt, moving together to achieve one common goal.

Beckett is the first to give in, clenching her teeth to keep in the sounds that are trying to escape her lips but she can't control the way her body arches. Her tightened muscles like steel bands before relaxing as she lets out a shuddering breath.

Her inner muscles clenching and releasing around the men inside her and neither can hold off the inevitable any longer.

The three collapse in a heap, chests heaving and hot, humid breaths mingling in the scant air between them.

They finally separate, now laying side-by-side.

Now finished for the night, everyone takes turns showering separately, well and truly worn out.

Leaving the ensuite bathroom once more; Castle finds himself looking upon the three detectives all laying together in the bed, piled tightly together.

He only now realizes that Beckett owns a king sized bed. A tight fit for three or more adults but it is possible, and to his delight, there's an open space and pillow on the side closest to him. Next to Beckett even!

He crawls into the bed and can't stop himself from wrapping an arm around Beckett's waist and pressing his body closely against hers. Her curves fitting perfectly against his body despite the fact that she herself is curled around Ryan.

As the three detectives and their resident writer drift to sleep, the last thought in the forefront of Castle's mind: _How long until we can do this again?_

* * *

_First and foremost I ask that everyone please let me know your thoughts on this story, my writing style, anything._

_The (main) reason for this is that I have decided to do a sequel. You know, one with an actual plot and not every chapter requiring an M rating :) Not that there's anything wrong with smut but it would probably get a little difficult to write M rated material every chapter for something like forty chapters._

_I will definitely make sure to let you all know when I begin posting the sequel by putting an update up on this story. It'll help any newcomers that don't read these notes know that there is a sequel too. That being said, I do have a rough outline of the story already in place to work from but I will be taking a few weeks to get a decent chunk of it written. That way I can make sure to get chapters out in a timely manner without forcing myself to write. That just doesn't make for good writing or publishing._

_To that end, I'm seriously thinking about having a beta for this next story. I haven't worked with one before, but after the updates I've made while writing this story, I can only imagine how much I could use someone helping make sure I don't rush and skip too many details. If you're interested please shoot me a message._

_Finally, I want to send out a huge thank you to everyone who has reviewed, followed, and/or favorited this story. Everyone has been amazing thus far, aside from the couple who didn't heed the warnings... you know who you are. Everyone else has been wonderful and I hope you all stick around to see the continuation of this little universe I've managed to create without actually meaning to. I mean, really, this was never originally meant to go past these couple chapters. The plot bunnies apparently had a different idea! Or maybe it was all of you. No matter onward and upwards... in a couple weeks._


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